1. Field of the Invention
The invention refers to an endless tread chassis for heavy vehicles, such as bucket-wheel excavators or wheeled loaders for example, comprising a rotary table traversing gear for cantilever arms, said chassis comprising at least four endless treads, at least two parallel endless treads of which are located at a greater distance from the longitudinal axis of the vehicle than at least two further treads being staggered in longitudinal direction of the vehicle. Vehicles which include rotary tables carry, as a rule, big cantilever arms which are connected with a base frame for being swingable around a substantially vertical swing axis. The cantilever arms are frequently counterbalanced by counterweight arms to such an extent that the supporting forces to be received by the chassis are received in parallel direction to the swing axis of the cantilever arm and approximately coaxially relative to the swing axis of the cantilever arm.
2. Description of the Prior Art
There is already known a plurality of constructions of endless treads chassis, in which is provided a plurality of endless treads for supporting the forces on ground. By means of such chassis, the supporting forces can be distributed over greater surface areas, so that sinking of the vehicle into ground can be avoided. In addition to vehicles having two endless treads essentially parallely arranged one relative to the other, there are also known vehicles having further endless treads. In case of only two treads, steering of the vehicles is effected by braking or accelerating one of both treads relative to the other. In case of more than two treads can be dirigible treads and be swingably linked to a supporting structure. If there are provided three treads, two treads are, as a rule, arranged in the rear area of the vehicle and in parallel relation one relative to the other and in parallel relation relative to the longitudinal axis of the vehicle, whereas a third tread is designed for being dirigible and is centrally arranged, as seen in longitudinal direction of the vehicle, in front of the not steered treads. In such constructions, the base frame for the rotary table is supported on three points and a supporting triangle is spread out. The swing axis of swivellable cantilever arms supported on such frames has been, as a rule, arranged in the known constructions within the center of gravity of the supporting triangle and thus within the point of intersection of the axes of gravity of the spread-out triangle.